Shock absorber mounting



April 10, 1951 R. LEWTON 2,548,167 'SHOCK ABSORBER MOUNTING Filed Nov.1, 1946 2 Sheets-Sheet 1 R033 Law fan.

HTTOR/VL'YS 2 Sheets-Sheet 2 Filed Nov. 1, 1946 g A/// v//// INVENTOR BYP038 Lewfon.

Patented Apr. 10, 1951 NT OFFICE SHOCK ABSORBER MOUNTING Ross Lewton,Highland Park Mich., assignor to Chrysler Corporation corporationofDelaware ighland Park, Mich., a

Application November 1, 1946, Serial No. 707,229 3-Claims (01. 267 8)This invention relates to shockabsorbersfor a I motor vehicles and moreparticularly to mountings for telescopic hydraulic shock absorbers relaetive to the sprung and unsprung portions of motor vehicles.

The invention herein will be described with reference to the frontsuspension of a motor vehicle although it is to be understood thatsimilar principles are involved in the rear suspension and that theinvention is applicable to rear suspension systems.

Heretofore it has been customary to connect the lower end of atelescopic hydraulic shock absorber to the lower control arm or thelower portion of the steering knuckle support of an independent wheelsuspension assembly. The upper portion of the shock absorber has beensometimes connected to the frame of the motor vehicle and sometimes tothe upper control arm of the in-. dependent suspension assembly. Thesemountings of the shock absorber have been found to have at least twoserious disadvantages.

The first disadvantage is that the reservoir containing the majorportion of the oil used-in the shock absorber is subjected to theoperating movements and vibrations of the lower control arm. Thisrepeated agitation induces a ,frothing and aeration of the oil. The oilbecomes foamy and the cushion effect of the shock absorber is lost underthese conditions. Permitting the vehicle to stand idle foran interval oftime will restore the oil to its former effectiveness, but continuedoperation under extremely bumpy conditions will cause a radical drop inthe efliciency of the shock absorber. This is sometimes loosely referredto as a cocktail shaker efiect. It is an object of the invention toconnect the reservoir of oil to the vehicle frame or sprung portionwhich is relatively stationary, andto thereby minimize the frothing ofthe oil.

The second disadvantage of these. ,shock absorber mountings is that themost effective travel of the shock absorber is not utilized to cushionthe upward movement of the unsprung portion of the vehicle. When thevehiclexwheel strikes a bump and rises, the conventional shock absorbermounting causes the shock absorberto shorten. For reasons to bedescribed herein this is not the most efiective cushioning movementofthe shock absorber. It is an .object'oi my insuspension assembly of avehicle embodying my' invention; Fig. 2 is an elevation taken on theline 2--2 of Fig. 1;

Fig- 3 is a vertical section of a shock absorber;

Fig. 4 is a section taken on the line 4-4 'of Fig. 3;

Fig. 5 is a section taken on the line 5--5 of Fig. 3; and

Fig- 6 is a section taken on the line 6-6 of Fig. 3..

In Fig. l the front cross member m of the vehicle frame is illustratedas having an upper control arm II and a lower control arm l2 pivotallymounted thereon. A steering knuckle support l3 has its end portionspivotally connected to the upper and lower control arms respectively. Asteering knuckle I4 is rotatably mounted on the steering knuckle supportin the usual manner. The steering knuckle support i4 is adapted to carrya wheel l5. A coil spring 16 is positioned with its axis insubstantially a vertical plane and the lower end. of this spring issupported by the lower control arm I 2. The upper end of the coil spring[6 supports the frame cross member! in the usual manner. 'A telescopichydraulic shock absorber IIof a type commonly used in the automotiveindustry, is supported in a substantially vertical position. A dependingbracket I 8 is secured to the frame by bolts IS. The lower portion ofthe bracket I8 is provided with a substantially horizontal shaft, onwhich the lower end of the shock absorber is rotatably vention to causethe shock absorber to lengthen it underthese conditions and thereby.-use it. to its best advantage.

-- Referring to the drawingsi x I H Fig-1. is a front elevationoithe-independent mounted and retained by the nut 21]. The upper andlower ends of the shock absorber are provided with rings 2| and 22. Ring22 is concentric with the shaft of bracket I8. The upper control arm IIhas a bracket 23 and shaft 2 i rigidly secured thereto. The upper ringof the shock absorber I1 is rotatably mounted on the shaft 24 andsecured thereon by the nut 25.

In operation when the wheel l5 strikes a bump it moves upward andthrough the steering knuckle support rotates the upper control arm IIand lower control arm l2 in a counterclockwise direction thus elongatingthe shock absorber I7 and compressing the coil spring I6. Downwardmotion of the wheel l5 under the influence of the spring [6 will reversethe direction of motion of the upper and lower control arms, the spring,and the shock absorber. In Figs. 3. .4, 5, and 6 a conventional type oftelescopic hydraulic shock absorber is illustrated. The construction ofthis shock absorber is conventional, but its operation 'must be un-s 3clerstood to realize the advantages inherent in my novel mounting. Thelower ring 22 is welded to a reservoir tube 30. The upper ring 2| isrigidly secured to a piston rod 3 A port member 32 is rigidly secured tothe lower internal portion of the reservoir tube 36 and supports acylinder tube 33. The upper portion of the reservoir tube is closed bythe threaded element 34 which receives the upper end of the cylindertube 33. A piston rod 3| penetrates the threaded element 34 and isadapted for axial reciprocation relative thereto. Suitable packing 35 isprovided in the threaded element 34 around the piston rod 3|. A pistonrod nut 36 is provided with a lateral flange 31 which supports a coilspring 38. A valve plate 39 is concentric with the piston rod 3| andurged upwardly in Fig. 3. A piston 40 is I secured to the piston rod 3|.A plate valve 4| A is positioned above the piston and retained inposition by a piston washer 42. The piston washer 42 is provided withorifices 43 and preferably does not have a diameter sufficiently largefor it to seal the cylinder tube 33. The plate valve 4| has a circularopening 44 therein which is illustrated in Fig. 4. The piston isprovided with relatively large orifices 45 which are aligned with theopening 44. The plate valve 39 is adapted to seal the orifice 45 againstany upward movement of oil through the piston and to resist downwardmovement of oil through the piston by compression of the spring 38.Piston 40 is provided with additional orifices 46 which are not alignedwith the circular opening 44 of the plate valve 4| so that the platevalve 4| is able to seal the orifices 46 against the downward movementof oil through the piston in these orifices. The plate valve 4| isrelatively weak and will permit the upward movement of oil through thepiston orifices 46. Port member 32 is provided with a plurality of ports41 which are connected with an oil reservoir 48 formed in the spacebetween the reservoir tube 36 and the cylinder tube 33. The port member32 has a substantially hollow interior to which the ports 4'! lead. Astar-shaped plate valve 49 is seated above an orifice 56 provided in theinternal portion of the port member 32. A spring 5| holds thestar-shaped valve 49 in position sealing the orifice 56 against thedownward movement of oil through orifice 50. The springs 5| arerelatively weak and permit the upward movement of oil through theorifice 5D. The star-shaped plate 49 is provided with a plurality ofrecessed peripheral portions '52. Supplemental orifices 53 are providedin parallel relationship with the orifice 50. The orifices 53 arelocated relative to the star-shaped plate valve 49 so that oil whichpasses the recessed portions 52 of the plate valve is free to enter theorifices 53. A conventional dust shield '54 is secured to the piston rod3| and disposed in concentric T612:- tionship with the reservoir tube.The space between the piston washer 42 and threaded element 34 forms anoperating chamber 55.

In operation when the piston rod 3| is extended relative to thereservoir tube 36, the piston 40 and piston washer 42, are moved upwardand this motion is resisted by oil in the chamber 55. The oil in thechamber 55 retards the movement of the piston 46 by a dashpot actionwhich permits limited displacement of the oil through the piston 46. Thedisplaced oil passes downward through the orifice 43 and continuesdownward through the slot 44 in plate valve 4| and enters the: orifices45 .inlthe piston. .The force impart! 4 ing such motion to the oil mustbe of sufficient magnitude so that the oil pressure against valve 39will overcome the spring 38 and permit oil to leave the orifice- 45 andpass downward over the piston rod nut 36. Thus the upward movement ofthe piston relative to the reservoir tube is permitted but restricted.The upward movement of the piston rod relative to the reservoir tubedraws oil from the reservoir 48 through the ports 41, the large orifices5D and unseats the valve 49. Some oil also passes through the orifice53. The reverse movement of the piston rod in a downward directionforces oil upward through the orifices 46 and unseats the plate valve 4|thereby filling the chamber 55. The restriction to the motion of thepiston is greatest when the piston is attempting to move upward relativeto the reservoir tube, for the discharge of oil is resisted by thespring 38 which is of relatively great strength compared to the platevalves in the system.

The mounting of the shock absorber with the lower end secured to therelatively stationary sprung portion of the vehicle minimizes theshaking and foaming of the oil in the reservoir.

The shock absorber is used to its best advantage where its elongationresists rising movement of the wheel and its relatively unresistedcompression accompanies the downward return movement of the wheel underthe influence of spring I6.

I claim:

1. In a motor vehicle having a frame and an independent wheel suspensionassembly, an upper control arm pivotally mounted at one end thereof onsaid frame, a lower control arm pivotally mounted at one end thereof onsaid frame, a coil spring positioned between said frame and anintermediate portion of said lower control arm, means supporting a wheelfrom the free ends of said upper and lower control arms, a bracketextending laterally of said frame between said spring and said wheel,and a vertical hydraulic shock absorber having a fluid reservoir elementand a piston, said reservoir element being spaced laterally of saidframe and mounted on said bracket at a location between said spring andsaid wheel and said'piston being operatively connected with anintermediate portion of said upper control arm.

2. In a motor vehicle having a frame and an independent wheel suspensionassembly, an upper control arm pivotally mounted at one end thereof onsaid frame, a lower control arm pivotally mounted at one end thereof onsaid frame, a coil spring positioned between said frame and anintermediate portion of said lower control arm, means supporting a wheelfrom the free ends of said upper and lower control arms, a bracketdepending from said frame and having an end portion located between saidspring and said means and at a higher elevation than the pivotalmoiinting of said lower control arm and a vertical hydraulic shockabsorber having a fluid reservoir element and a piston, said reservoirelement being mounted on said bracket end between said spring and saidmeans and said piston being operatively connected with an intermediateportion of said upper control arm.

3. In a motor vehicle having a frame and an independent wheel suspensionassembly, an upper control arm pivotally mounted at one end thereof onsaid frame, a lower control arm pivotally mounted at one end thereof onsaid frame and spaced vertically from said upper control arm, acoil'spring positioned between said frame and an intermediate portion ofsaid lower control arm, REFERENCES CITED mtaans supportmg Wheel from thefree ends, of The following references are of record in the said upperand lower control arms, a depending file of this patent:

bracket extending laterally of said frame and hav- 1 ing a shockabsorber mounting portion located 5 UNITED STATES PATENTS between saidvertically spaced upper and lower Number Name Date control arms andlocated laterally between said 2,138,513 Rossman et a1. Nov. 29, 1938spring and said wheel and a vertical hydraulic 2,188,909 Leighton Feb.6, 1940 shock absorber having a fluid reservoir element 2,188,952Leighton Feb. 6, 1940 and a piston, said reservoir element being mount-1:; 2,189,651 Leighton Feb. 6, 1940 ed on said bracket mounting portionbetween said 2,260,634 Mullner Oct. 28, 1941 control arms and betweensaid spring and said 2,342,381 Thornhill Feb. 22, 1944 wheel and saidpiston being operatively connected with an intermediate portion of saidupper con- FOREIGN PATENTS trol arm. 15 Number Country Date ROSS LEWTON.1 ,81 France May 31, 1937

